Field Coil Winding Assembly Oxidation Adhesion
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional field coil winding assemblies in dynamoelectric machines face issues with thermal and mechanical stresses, leading to degradation of turn insulation systems, turn shorts, and adhesion loss, which can cause blockage of ventilation paths and reduce thermal resistance, with existing methods being costly and impractical for enhancing mechanical integrity.
Innovation Solution
A method involving cleaning and oxidizing copper coils to develop a copper oxide layer, followed by applying a turn insulation system with glass fiber-reinforced high-temperature materials and a suitable adhesive, such as Bisphenol-A-based epoxy or polyamideimide, and curing them before stacking in rotor slots, to enhance mechanical and electrical integrity.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional adhesive chemistry is used for turn insulation, then adhesion is provided, but thermal resistance increases and adhesion capability decreases under thermal stress
Solution Approach 1:
The patent changes the chemical composition parameters of the adhesive system by incorporating copper oxide nanoparticles and specific ratios of coupling agents (silane and titanate) to enhance thermal stability while maintaining adhesion. This modifies the adhesive's physical and chemical properties to withstand higher temperatures without degrading adhesion capability.
Solution Approach 2:
The patent creates a composite adhesive material by combining organic adhesive base with inorganic copper oxide nanoparticles and multiple coupling agents. This composite structure provides both the adhesion properties of the organic matrix and the thermal stability of the inorganic nanoparticles, resolving the contradiction between adhesion and thermal resistance.
2Reliability
If copper coils are cleaned and oxidized to develop copper oxide layer, then adhesion is enhanced, but manufacturing complexity and cost increase
Solution Approach 1:
The patent performs preliminary cleaning and oxidation of copper coil surfaces before adhesive application. This preliminary action creates a copper oxide layer that enhances adhesion, and the process is integrated into the manufacturing workflow to minimize additional complexity.
Solution Approach 2:
The copper oxide layer acts as an intermediary between the copper coil surface and the adhesive. This intermediate layer improves chemical bonding and adhesion strength, making the enhanced adhesion achievable through a relatively simple surface treatment process.
3Temperature
If glass fiber-reinforced high temperature materials are used for turn insulation, then thermal resistance improves and mechanical integrity is enhanced, but manufacturing cost and process complexity increase
Solution Approach 1:
The patent uses glass fiber-reinforced polyimide as a composite turn insulation material. The glass fibers provide mechanical strength and thermal stability, while the polyimide matrix provides electrical insulation and flexibility. This composite approach achieves high thermal resistance and mechanical integrity through material selection rather than complex manufacturing processes.
Solution Approach 2:
The patent selects specific high-temperature materials (glass fiber-reinforced polyimide, polyester, or novolac epoxy) with defined thermal and mechanical parameters. By carefully selecting materials with appropriate glass transition temperatures and thermal properties, the patent achieves the required thermal resistance without unnecessary manufacturing complexity.
4Reliability
If turn insulation system is applied with adhesive, then mechanical and electrical separation is provided, but adhesion loss occurs under thermal and mechanical stress
Solution Approach 1:
The patent develops a composite adhesive system combining organic adhesive with inorganic copper oxide nanoparticles and multiple coupling agents. This composite structure maintains adhesion stability under thermal and mechanical stress by distributing stress through the nanoparticle network and enhancing chemical bonding through the coupling agents.
Solution Approach 2:
The patent modifies the adhesive's chemical composition to include specific ratios of coupling agents and nanoparticles, changing its physical and chemical parameters to resist thermal degradation and mechanical stress. This ensures adhesion stability while maintaining electrical insulation properties.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
The solution effectively reduces the risk of turn shorts and adhesion loss, improves thermal resistance, and maintains mechanical integrity, providing a robust and durable field coil winding assembly that withstands high temperatures and stresses.
Implementation Method 1
developing, after the cleaning, a copper oxide layer on each of the copper coils by oxidizing each of the copper coils in a solution
Implementation Method 2
The adhesive chemistry limits the choice of adhesive for turn insulation user in large dynamoelectric machines
Implementation Method 3
developing, after the cleaning, a copper oxide layer on each of the copper coils by oxidizing each of the copper coils in a solution
Data Source
AI summary
A method for preparing a field coil winding assembly including cleaning a plurality of copper coils followed by developing, after the cleaning, a copper oxide layer on each of the copper coils by oxidizing each of the copper coils in a solution. After the developing, each of the copper coils is rinsed followed by drying. After the drying, a turn insulation system is applied to each of the copper coils. The turn insulation system includes a turn insulation and an adhesive. The turn insulation includes at least one of a glass fiber re-enforced polyamideimide, a glass fiber re-enforced polyester, or a glass fiber re-enforced high temperature novolac epoxy. After the applying, each of the copper coils with the turn insulation system is cured. The plurality of copper coils with the turn insulation system are stacked in each of a plurality of rotor slots in a rotor.